Question

Linear momentum of a body is increased by $40\%$. Then percentage increase in its kinetic energy is:

• A. $120\%$
• B. $80\%$
• C. $70\%$
• D. $96\%$

Answer 1

The correct option is B. $80\%$.

We know that,

Linear momentum = $p=mv$

Kinetic energy = $KE=\frac{1}{2}m{v}^2$

$\Rightarrow KE=\frac{p^2}{2m}$

$\Rightarrow \frac{\Delta KE}{KE}\times 100=2\times \frac{\Delta p}{p}\times 100=2\times 40=80$%.